The subject of the present invention is a synergistic fungicidal composition comprising a compound analogous to strobilurin and a process which makes use of the said composition and which is intended for the curative or preventive protection of crops against fungal attacks.
Compounds analogous to strobilurin with a fungicidal effect are known, in particular from European Patent Application EP 253213 or 398692 or from international Application WO 92/08703, which make it possible to prevent the growth and the development of phytopathogenic fungi capable of attacking crops.
However, it is always desirable to improve the spectrum of activity and the effectiveness of such compounds with a fungicidal effect or to reinforce them by combining them with other molecules in order to obtain a more effective product (combination with a systemic fungicide, these fungicides instead being molecules of xe2x80x9ccontactxe2x80x9d type) or alternatively to prevent the appearance of fungal strains which are resistant to these new fungicides.
It is also highly desirable to have available fungicidal products which enjoy an improved persistence of effect, likely to space out in time the number of plant-protection treatments necessary for satisfactory control of the parasites.
It is, in any event, particularly advantageous to be able to decrease the amount of chemicals distributed in the environment, while ensuring high-performance protection of crops against fungal attacks.
It has now been found that one (or a number) of the above objects could be achieved by virtue of the fungicidal composition according to the present invention.
The present invention accordingly provides a synergistic fungicidal composition comprising at least one compound A of formula (I): 
in which:
A is the nitrogen atom or the xe2x80x94CH group,
B is the xe2x80x94OCH2xe2x80x94 or xe2x80x94CH2Oxe2x80x94 or xe2x80x94CH(CH3)xe2x80x94Oxe2x80x94Nxe2x95x90CHxe2x80x94 or xe2x80x94CHxe2x95x90Nxe2x80x94Oxe2x80x94CH(CH3)xe2x80x94 group or the group 
R1 is an alkyl group containing 1 to 4 carbon atoms, preferably the methyl group,
R2 is xe2x80x94OCH3 or xe2x80x94NHCH3,
X is a halogen atom, the cyano group or an alkyl or haloalkyl group containing 1 to 4 carbon atoms, preferably the methyl or trifluoromethyl group,
n is equal to 1 or 2, with, when n is equal to 2, the possibility of having different X groups,
and at least one fungicidal compound B chosen from the group consisting of phosphorous acid and derivatives thereof, for example metal phosphites, such as fosetyl-Al, and alkali metal or alkaline-earth metal salts of phosphorous acid. The compositions will generally contain one compound A.